Event Details

The issue that proliferation of antibiotic-resistant pathogens may be linked to antibacterial emerging contaminants (ECs) in the aquatic environment has necessitated a better understanding of the environmental fate of these ECs. Metal oxide-facilitated transformation is likely an important degradation pathway of ECs at soil-water interfaces. Results of our previous work showed that many ECs are susceptible to Mn and Fe oxide-facilitated oxidation. Current research centers on the development of binary metal oxide mixtures containing Mn/Fe oxides and a second metal oxide (e.g., Al2O3, FeOOH, Fe2O3, SiO2 or TiO2). The goal is to examine the potential interactions between the two oxides and understand how these interactions affect the redox activities of Mn/Fe oxides. Our data suggest that the second metal oxides typically lowered the reactivity of MnO2 through heteroaggregation (FeOOH and Fe2O3), surface complexation/precipitation (Al2O3 and SiO2), or competitive adsorption (TiO2).To eliminate the accumulation of ECs in the environment, we examine the efficacy of polymeric resins in the removal of both neutral and ionic ECs. Experimental results show that polymeric sorbents with variable pore structures and surface functional groups have significantly different removal efficiency towards the target contaminants. In addition to hydrophobic interactions, hydrogen-bonding is predominantly responsible for the adsorption of neutral ECs by three non-ionic resins (XAD-4, XAD-7 and MN200). Poly-parameter linear free energy relationships are being developed to predict the removal of ECs based on the physic-chemical and structural properties of both the ECs and the sorbents. Most of the exhausted sorbents can be readily regenerated by either weak acid/base solution or organic solvents. Overall, this research will establish adsorption by polymeric sorbents as a potentially attractive drinking water and wastewater treatment technique.